Imagine two futures for the transportation system of the Commonwealth of Massachusetts.

In one, the air is cleaner. It is more convenient to use an improved public transit system ad to drive less, so most households only own one car. There are fewer traffic jams because fewer people travel via automobile. There are more sidewalks and bike lanes, so many people walk or bike to their jobs, schools, and other destinations. People feel a little richer with extra money in their pocket, due to less spending on gasoline, parking, and auto maintenance. Bay Staters are healthier as a result of reduced pollution and increased physical activity.

In the second future, imagine the opposite trends. More cars are on the road, increasing traffic congestion, pollution, and emissions that cause global warming. Public transit is less convenient and less available because it is often broken down and hasn’t expanded with the economy. Walking and bicycling in- frastructure remains unimproved. More col- lisions result in more deaths and injuries. We spend more filling up our tanks and repair- ing our vehicles more frequently, and the state spends more to repair the increased wear on roads. Bay Staters have less money, less time, and are less healthy.

The benefits of reduced driving are some- times difficult to see, but hugely important. Many dramatic gains remain unrecognized because they are indirect, gradual, or result from avoided collisions and health prob- lems that people don’t expect will happen to them in the first place. In our daily lives, it is difficult to assess the value of reduced costs that would have been borne by others or consequences that didn’t occur.

To make these benefits clear, this report quantifies the gains that would be enjoyed by the Commonwealth and its residents re- sulting from a one percentage point reduc- tion in the growth rate of driving. Starting with the state’s official driving forecasts, a one percentage point reduction in the growth rate of driving from 2015 to 2030 would bring major economic, environmen- tal, and public health benefits, with annual savings increasing each successive year.

• $785 million less spent on fewer automo- bile collisions and resulting consequences

• $446 million less spent on vehicle repair • $224 million less spent on road repair

Tallying up the benefits that would result over the course of the next 15 years, the combined economic savings resulting from a one percentage point reduction in the driving growth rate below official forecasts are estimated to reach $20.1 billion, consist- ing of:

To put these sums in context, the total economic savings of a one percentage point reduction in the VMT growth rate from 2015 to 2030 is enough to provide any one of the following:
Groceries for 180,455 American house- holds for the entire period;1 or Daycare costs for 81,558 Massachusetts infants in daycare fulltime for the pe-riod;2 or Mortgage payments for 92,746 aver- age Massachusetts households for the period.3

A one percentage point reduction in the vehicle-miles traveled (VMT) growth rate would also result in 267.6 million fewer gallons of gas consumed annually by 2030, and 2.6 billion fewer gallons of gas con- sumed cumulatively over the course of the next 15 years. This is the equivalent of every household in Massachusetts saving nearly a thousand gallons of gasoline over the period.4

This reduction in gasoline consumption would prevent an estimated 2.4 million metric tons of carbon dioxide from being released into the atmosphere annually by 2030, and an estimated 23.3 million metric tons of carbon dioxide cumulatively from being emitted from 2015 to 2030. Accord- ing to the U.S. Environmental Protection Agency’s Greenhouse Gas Equivalencies Cal- culator, the annual carbon emissions savings by 2030 would be equivalent to taking more than 500,000 cars off the road that year. 5

The carbon savings are especially important because the transportation sector has been the biggest and fastest growing source of carbon-related emissions in Massachusetts in recent decades.6 Addressing transpor- tation sector emissions by reducing the number of driving miles will significantly improve our ability to meet the Com- monwealth’s commitment to curb global warming, as set forth by the Massachusetts Global Warming Solutions Act of 2008.

Furthermore, there are significant public health benefits from reduced driving miles.

Burning less gasoline reduces the amount of pollution released into the atmosphere. Air particulate matter associated with the transportation sector has been linked to nearly 53,000 premature deaths a year in the United States, according to a recent study conducted by the Massachusetts In- stitute of Technology.7 As individuals drive less, studies also find they are more physi- cally active and less likely to be obese, or suffer from other chronic illnesses linked to physical inactivity, such as cancer, diabe- tes, and heart disease.8 The good news is that increased walking, bicycling, and use of public transportation can help offset these risks.

The State has adopted a goal of tripling the number of public transit, walking, and bicycling trips by 2030. State and local transportation decisions should be oriented around attaining this goal and enabling reduced driving more generally. The criteria for selecting which transportation projects receive priority for state investment should be revised to prominently consider the reduction of VMT, to give greater weight to public health and environmental factors, and to ensure that the most useful projects receive priority, regardless of the mode of transportation the project utilizes.

While it has long been a transportation holy grail to accurately measure the VMT impacts of certain transportation choices, that does not mean it is not a worthwhile endeavor. Capturing the benefits of re- duced driving between now and 2030 will require resources and new state and local policies and incentives to enable Bay State residents to drive less and take advantage of other forms of transportation more. Finally, the state should regularly publicly disclose its progress in meeting these goals.

Now, more than ever, it is imperative that we introduce policies that reduce driving miles, as total vehicle miles have drifted upwards recently, after years of decline. This report shows that even a modest reduction in driving miles will deliver large benefits to the economy, the environment, and public health.